1. Field of the Invention
The present invention is related to methods and devices for detecting distance, identifying positions of targets, and identifying a current position in a smart portable device, and more particularly, to methods and devices capable of enhancing functions of the smart portable device, so as to detect distance, identify positions of targets, and identify the current position of the smart portable device.
2. Description of the Prior Art
With the advancement of technology, a smart portable device includes various functions, such as voice communication, wireless networking, navigation, photography, video display, etc. The navigation function is performed with a global positioning system (GPS), to plan a route toward a destination set by a user according to existed map data, such that the user can reach the destination in a shorter path or with less time. To accomplish the navigation function, the smart portable device must include a GPS receiver and related navigation software.
In general, when using the smart portable device for navigating to a destination, the user has to confirm information of the destination, such as name, address, coordinate, etc., and input the information to the smart portable device, to perform route planning tasks. However, in some occasions, the user cannot acquire information of the destination, and therefore cannot use the navigation function even if the GPS receiver and related software operate regularly. For example, when the user discovers an unknown spot or object (e.g. building, mountain, temple, etc.) and desires to visit, the user cannot perform navigation via the smart portable device since no specific information of the spot can be gathered. Besides, if the GPS receiver is not embedded in the smart portable device or malfunctions due to breakdown, bad weather, or being shielded, a current position of the user cannot be identified, such that the user cannot be navigated to a spot even if the user recognizes the name or address of the spot.
Therefore, how to enhance the navigation function of the smart portable device has been one of the major targets of the industry.